Two recent articles illustrate contemporary scientists’ widely divergent perspectives on the hormesis phenomenon. On one hand, Edward Calabrese claims that “[T]he preponderance of evidence supports the consideration of hormesis as the default dose-response model for all types of endpoints.”1 On the other hand, Kristina Thayer and her colleagues state the following:
The claims and projections of health benefits from exposures to environmen-
tal toxicants and carcinogens are based on untested assumptions and disre
gard numerous well-established scientific principles that underpin a public
health–protective approach to regulating exposure to toxic substances. If
hormesis were used in the decision-making process to allow higher exposures
to toxic and carcinogenic agents, this would substantially increase health risks
for many, if not most, segments of the general population.2
This book has emphasized that these disagreements are aggravated by the significant amounts of money at stake in scientific conclusions on hormesis. For example, the industrial community tends to be much more sympathetic than the environmental and public-health communities to claims HG, HP, and HD.
We saw in chapter 4 that powerful stakeholders with deep pockets can pursue a variety of strategies to obtain research results that serve their interests in policy-relevant cases like hormesis. Partly because of this, scholars in the science-policy community argue that collecting more information is not always sufficient to resolve disputes. In fact, Roger Pielke Jr. and Daniel Sarewitz make the surprising claim that, rather than scientific uncertainty breeding political conflicts over how to act, the causal arrow often runs in the opposite direction—disagreements over social values breed scientific uncertainty. As Sarewitz puts it:
[T]he growth of considerable bodies of scientific knowledge, created especially
to resolve political dispute and enable effective decision-making, has often
been accompanied instead by growing political controversy and gridlock.
1. Calabrese, “Hormesis: From Marginalization to Mainstream,” especially 134.
2. Thayer et al., “Fundamental Flaws.”